Fluid operated power hammer



June 1954 c. A. EACH ET AL 2,630,282

FLUID OPERATED POWER HAMMER Filed NOV. 15, 1951 .26 ,2 4a a, 44 4 0 gzFlEil- ,r iwTl '25 g 4 laweniom: CZYDE ,4. [46H and 57EP/7E/VM Patented June 8, 1954 FLUID OPERATED POWER HAMMER Clyde A. Each and Stephen M. West, Chicago, Ill.

Application November 15, 1951, Serial 'No. 256,522

4 Claims.

The present invention relates to an improved power hammer and more particularly to a fluid operated hammer apparatus especially suitable for fracturing a specimen of metal in order that its grain structure may be visually examined.

In its manufacture it is necessary to check the carbon content of low carbon steel frequently during processing. This is ordinarily done by pouring a sample of the molten metal into a small mold, allowing it to cool and solidify and then fracturing the hardened metal to exposure the grain structure. The melter can then roughly determine the carbon content of the steel by visually examining the exposed grain structure at the fracture. In order that the carbon reading be as accurate as possible it is essential that the fracture in the sample be free of any shearing effect which would distort the natural grain structure of the material. Prior to our invention it was customary to fracture the sample by striking it manually with a sledge hammer. This method was not altogether satisfactory since the sample was not always struck squarely which resulted in fractures which showed shear effects. When this happened it was necessary to process another sample. This, of course, wasted time and frequently jeopardized the quality of the steel being made by affecting its treatment.

It is accordingly an object'of our invention to provide a sample breaking apparatus which is fluid operated and which functions to produce a cleanly fractured specimen, free of any shear effect.

Another object of our invention is to provide a sample breaker which is rugged in construction and inexpensive to manufacture and operate.

It is a further object of our invention to provide a test breaker which has safety features incorporated therein which protect the workman from injury while in operation.

These and. other objects will become more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a top plan view;

Figure 2 is a side elevational view; and

Figure 3 is a side elevational view partly in section taken on the line IIIIII of Figure 1.

Referring more particularly to the drawings, reference numeral 2 indicates an elongated platform which may be supported by a pair of vertical supports 4 and 4' which in turn may rest on a pair of base plates 6. A V-notched samplesupporting anvil 8 is attached to the upper surface of the platform adjacent its one end. A hammer 10, having a lever arm portion l2 and a striking head I4, is pivotally mounted in brackets l6 intermediate the ends of the platform 2 by means of a pin [8. A bracket 20, having a stud 22 projecting therefrom, is welded or otherwise attached to one edge of the lever arm intermediate the striking head and the brackets l6. One outer edge 24 of the bracket is shaped to provide-a flush contact with a stop member 26 when the hammer is in normal resting position as shown in Figure 2. The stop member 26 is attached to and projects upwardly from the upper surface of the platform 2 adjacent the brackets H5.

The center distance between the brackets l6 and the anvil 8 is such that when the hammer swings about its pivot pin I8 the striking head [4 strikes the anvil. The bracket 20 is positioned along the edge of the lever arm l2 so that it will contact the stop member when the hammer is brought back to initial resting position.

A fluid cylinder 28, which may be air operated, is pivotally supported at its rear end in a bracket 30, which is attached to the surface of the platform 2 adjacent the end thereof remote from the anvil 8. The piston rod 32 of fluid cylinder 28 is pivotally connected at its free end with a pin 34 which is fitted through the body of the lever arm". A link 35, which is attached at one end to the portion of pin 34 remote from the rod 32 and at its other end to the pivot pin I 8, is provided to eliminate any distortion in the movement of the hammer due to unequal side strain.

Another fluid cylinder 36, which may be smaller than the fluid cylinder 28, is disposed adjacent the cylinder 28 with its rearward end pivotally supported in a bracket 33. The piston rod 40 of a cylinder 36 is pivotally connected with the stud 22 which projects from the bracket 20. The cylinder 36 is provided with an air inlet 42 above its piston adjacent its upper end while the cylinder 28 has an air inlet 44 at its lower end below its piston. Flexible air hoses 48 and 50 are attached to the air inlets 42 and 44 respectively and lead therefrom to a common four-way valve 46. An air supply line 52 is also connected with the valve 46. Support 4' is bored, as shown in Figures 2 and 3, in order to function as an air reservoir to which the air supply line 52 is con nected as at 54 in order to maintain a constant volume of air in the system.

A metal mesh cage 56, having a door 58 at one end adjacent the anvil 8, projects upwardly from the platform 2 to enclose the entire apparatus. A bracket 60 is provided on the lower part of the door 58 and is positioned to engage a compression spring 62 which is attached to a rod 64 which 3 passes through a vertically slotted bracket 65. The rod 6% is one element of a toggle assembly 66 which consists of a toggle lever 68 attached to one end of the rod 64 and another rod ill which is attached to the toggle lever 68 on the end thereof opposite the rod 64. The opposite end of the rod 10 is operatively attached to the handle 12 of a quick acting valve 74 which is disposed in the air hose ac to control the air being admitted to the cylinder 28.

In operation, when it is desired to fracture a sample W the operator opens the door 58 of the cage and places the sample in the V notch of the anvil 8. The opening of the doorcauses compression of the spring 62 by moving the rod 64 a to the right, as viewed in Figure 1, by means 'of the bracket 60, a link Shanda bell crank "63. Movement of the rod 64 to the right causes the toggle lever 63 to pull rod II! to the left to turn the handle 12 of the valve to closed position to prevent any air from being admitted to the cylinder. Thus the toggle assembly together with'the bracket 68, link-Bl and bell crank 53 constitutes a safety device to safeguard against W movementof the hammer toward the anvil while the operator is placing a sarnple thereon. Closing of the'door causes movement of the rod 64 to the left and movement of the rod 10 to the right to reopen the valve "14.

After the sample-has been placed the door of the cage is closed and the four-way valve 58 is manipulated to" admit air to the cylinder 28 and at"- thesametime exhaust-the cylinder 36. In-

troducing-air into the cylinder 28 causes the piston rod- 32 to-be thrust forward thereby swinging the hammer i5 so that the striking head l4 travels-in-an 'arcuate path to' forcefully strike the sample' W resting on'the anvil and fracture it. After the sample or specimen has been fractured the four-way valve is again manipulated to simultaneously exhaust the' air' from the cylinder 23-and introduce-airinto thecylinder 36, The

: introduction of air into the inlet 4211f the cylinder SS'causes the piston rod i'J to withdraw into the cylinder-thus swinging the hammer I!) back to its "initial' r'esting position with brackct 26 rest- I ing on stop memberddafter which the four-way valve is returned to neutral or 01f position.

'A spring ld which is attachedat one end-to the handleof the four' way valve and at its other #endto the-platform 2,:is' provided' to maintain the four-way valve in neutral position except when being manually operated.

A light- !8 may be provide'd'above' the cage 56 as shown'inFigure 2 to illuminate the anvil *8.

While one embodiment of our invention has been shown and described it will be apparent that other adaptations and modifications may be -made without departing from -the' scope of the following claims.

We claim: 1. Apparatus :;for fracturing a specimen of -metal=or the like comprising apivotally mounted hammer having a striking head, an anvil adjacent said hammer for supportingsaid specimen inthe path ofsaid striking head a fluid cylinder'ad'jacent said hammen ai piston slidably disposed insaid cylinder, -apiston rodattached to said piston and projecting therefrom outwardly of -said cylinder,=said piston rod-being connected to said hammeratits projecting end, a fluid sup- =-p'1yline connected With -saidfluid cylinder,-control means for :actuatingsaid fluid cylinderto -formg ahammer-having a striking head pivotally mounted on said platform intermediate the ends thereof, an anvil on said platform adjacent one "end thereofadapted to support said specimen,

said anvil being disposed in the path of the striking head of said hammer, a first fluid cylinder having a piston rod projecting therefrom .pivotally mounted on said platform adjacent said hammer withsaid piston rod pivotally connected with the hammer, a" second fluid cylinder having a piston rod projecting therefrom pivotally mounted on said "platformadjacent said first named "cylinder, the piston rod of said second cylinder being pivotally connected with said hammen and means connected with said cylinder for actuatingthesame; said means including a fluid supply line connected with a pressure fluid sourcejthe end of said supply line remote from said pressure fluid source being divided into a first branch "and a second branch, said first branch bcing 'connected with the bottom of said first cylinder and said second branch being connected with the upper portion of said second cylinder; and a four-way valve disposed in said fluid" supply line at the junction of said branches for simultaneously directing fluid into 'one cylinder and exhausting fluid from the other to actuate said hammer.

3. Apparatus for fracturing a specimen of metal or the likeas-defined in claim 2 including a pair "of spacedwertical supports for said platform, one or said *suppo'rts being hollow to constitute a 'fluidreservoir, a fluid inlet in said support" connected 'witha pressure fluid supply source, and 'an outlet onsaid hollow support connectedwithsaidileiiible; fluid supply line.

-4.Apparatus for fracturing a specimen of metal or the like-as defined'in claim 2 characterized bya'cagesurrounding said hammer and anvil, a door in said cage adjacent said anvil,

a valve having a handle lever connected in said *fluidsupply' line adjacent the bottom of said first named fluid cyliriderfor shutting off the fluid "supply thereto, and togglemsans connecting said door and said handle lever-whereby said valve'is operated to maintain fluid cylinder inoperative when said door-is opened.

References. Cited inthefile of this patent UNITED- STATES .PATENTS France; June"9,' 1922 

